The present invention relates generally to the field of orthopedic bandaging articles, such as casts and splints, for immobilizing body parts, and more specifically to an improved construction for a moisture-curable resin bandaging article and packaging system therefor.
Orthopedic bandages used in the treatment of injuries requiring immobilization of a body member are generally formed from a strip of fabric or scrim material impregnated with a substance which hardens after the strip has been wrapped around or used to support the body member. Traditionally plaster-of-Paris has been used as the hardening substance.
Typically plaster-of-Paris has been used to construct a cast or splint for an injured body member by first applying a protective covering layer of cotton fabric or the like to the body member and then applying the fabric impregnated with plaster-of-Paris which has been wetted in water immediately before application. Plaster-of-Paris is generally considered easy to work but also has numerous disadvantages. For example, several layers of the impregnated and wetted fabric must be applied to obtain a sufficient strong cast or splint, and plaster-of-Paris has a relatively low strength to weight ratio which results in a heavy and bulky bandage. Plaster-of-Paris bandages are also slow to harden, sometimes requiring a few days to reach maximum strength. Also, plaster-of-Paris breaks down in water which limits or prohibits some activities of a patient, such as bathing.
A significant advance in the art of hardenable bandaging has been made in the development of moisture-curable resins which are impregnated or coated onto fabrics which are maintained in moisture-free conditions until use. Another development in this art has been the use of fiberglass fabrics or substrates onto which the resin is impregnated or coated. U.S. Pat. No. 4,411,262 to von Bonin et al. discloses a constructional material which is stable in moisture-free storage conditions, but which hardens upon exposure to moisture, either by direct wetting or by the moisture in the air. U.S. Pat. No. 4,433,680 to Yoon discloses a prepolymer which is used with moisture-curable resin to give the bandage increased shelf stability and improved set time.
Compared to plaster-of-Paris, curable resin products are lightweight, have a relatively high strength to weight ratio and can be made relatively porous. Prior art moisture-curing bandages include layers of resin impregnated substrates arranged between layers of closed cell foam, open cell foam, various fabrics and sometimes enveloped in tubular fabrics or stockinets. If the several layers of substrates, fabrics, foams, etc. are not held together, once wetted, they can move relative to one another and result in messy application or improper positioning of the layers to harden in the most effective manner. In addition, since most bandaging products have a side which is specifically suited for application to the skin of the patient while the other side is specifically suited to be the outer side, when the substrates, foams, etc. are enveloped in stockinets, it is difficult for the doctor or technician to determine which side should be applied to the skin.
The prior art bandages have typically been individually packaged in pouches made of metal foil and plastic film laminated together. U.S. Pat. Nos. 4,770,299, 4,869,046 and 4,899,738 to Parker disclose moisture-curable bandaging products in a convenient roll form in which the packaging is tubular and coextensive with the bandaging product. A desired length of bandaging product is removed from the package by cutting through the package and bandaging product and then resealing the roll. A disadvantage of this configuration is that once the sealed package is cut, air enters the roll package and when the package is resealed the atmospheric moisture from the air causes some of the bandaging product, particularly near the seal, to harden. Subsequent use of the bandaging product requires that the hardened areas be discarded resulting in waste which is a significant economical drawback since the effective cost of the product is increased. Another disadvantage of the coextensive package and bandaging product configuration is the difficulty in cutting two layers of the strong foil-plastic film packaging material, top and bottom, as well as several layers of fiberglass substrate, and any intervening fabric layers or resin. Tied to this problem is the need to clean the cutting tools, such as scissors, used to cut the package/bandaging product since they can easily become coated with resin.
The moisture-curable resin bandaging products discussed above still possess disadvantages which complicate their use and increase the effective cost of the products.